Hindered piperidine carboxamide acids and metal salts thereof

ABSTRACT

Compounds having the formula   WHEREIN R1 and R2 are lower alkyl or form a cycloalkyl ring, R3 is hydrogen, alkyl, Beta -methoxyethyl, alkenyl, propargyl, benzyl or alkyl substituted benzyl, R4 is alkylene, alkyl-thio-alkyl or alkyl-oxo-alkyl, M is hydrogen or a metal, and Z IS AN INTEGER OF FROM 1 TO 4, ARE GOOD STABILIZERS AGAINST ACTINIC RADIATION. These compounds are prepared, for example, from 4-amino-2,2,6,6tetramethylpiperidine and succinic anhydride to give N-(2,2,6,6tetramethylpiperidyl-4)succinamic acid. The metal salts of the acids are readily prepared by reacting the acids or their salts with a reactive form of the metal or metal complex.

United States Patent [191 Ramey et al.

[ Sept. 23, 1975 HINDERED PIPERIDINE CARBOXAMIDE ACIDS AND METAL SALTS THEREOF [75] Inventors: Chester E. Ramey, Spring Valley;

John J. Luzzi, Carmel, both of NY.

[73] Assignee: Ciba-Geigy Corporation, Ardsley,

22 Filed: Dec. 28, 1973 211 App]. No.: 429,327

[52] US. Cl. 260/270; 260/45.8 N; 260/293.66;

260/293.86 [51] Int. Cl. C07D 211/58 [58] Field of Search 260/270, 293.66, 293.86

[56] References Cited UNITED STATES PATENTS 12/1972 Murayama et al..... 260/293.86 8/1974 Holt et al 260/293.62

Primary Examiner-G. Thomas Todd Attorney, Agent, or Firm-Charles W. Vanecek [57] ABSTRACT Compounds having the formula wherein R and R are lower alkyl or form a cycloalkyl ring,

R, is hydrogen, alkyLB-methoxyethyl, alkenyl,

propargyl, benzyl or alkyl substituted benzyl,

R is alkylene, alkyl-thio-alkyl or alkyl-oxoalkyl,

M is hydrogen or a metal, and

z is an integer of from 1 to 4, are good stabilizers against actinic radiation.

These compounds are prepared, for example, from 4-amino-2,2,6,6-tetramethylpiperidine and succinic anhydride to give N-(2,2,6,6-tetramethylpiperidyl-4)succinamic acid. The metal salts of the acids are readily prepared by reacting the acids or their salts with a reactive form of the metal or metal complex.

9 Claims, No Drawings HINDERED PIPERIDINE CARBOXAMIDE ACIDS AND M'ETAL SALTS THEREOF BACKGROUND OF THE INVENTION discoloration and cmbrittlement caused by exposure to light, especially ultraviolet light.

It is known that actinic radiation, particularly in the near ultraviolet region, has a deleterious effect on both the appearance and properties of organic polymers. For example, normally colorless or light colored polyesters yellow on exposure to sunlight as do such cellulosics as cellulose acetate. Polystyrene discolors and cracks, with accompanying loss of its desirable physical properties when exposed to actinic light, while vinyl resins, such as polyvinyl chloride and polyvinyl acetate spot and degrade. The rate of air oxidation of polyolefins such as polyethylene and polypropylene is materially accelerated by ultraviolet light.

It has been proposed to stabilize polymeric materials against ultraviolet light deterioration by the use of various types of ultraviolet absorbers. Thus, US. Pat. No. 3,004,896 discloses for this purpose 2(2-hydroxyphenyl)benzotriazole derivatives, while U.S. Pat. No. 3,189,630 discloses certain metal salts of hydroxybenzoic acids which are useful as actinic stabilizers in synthetic polymers.

Additionally, in US. Pat. No. 3,l20,540 there is discussed the reaction of substituted 4-piperidonal compounds with acid anhydrides having the formula (CH.,) oc O (=O where n is l to 4, to yield bis(polymethyl )-4-piperidinol alkanoates. In the example of this patent the probable formation of is mentioned as an intermediate in the synthesis of the bis(hydrogen sulfate)salt of bis( 1 ,2,2,6,6-pentamethyl- 4-piperidyl)succinate. The compounds of US. Pat. No. 3,l20,540 are taught to possess significant pharmacological activity in lowering blood pressure. We have now found that certain hindered piperidine carboxamide acids and metal salts thereof stabilize organic substrates against the degradative effect of ultraviolet light.

DETAILED DISCLOSURE The present invention is accordingly directed to a new class of ultraviolet light stabilizers which consist of a compound of the formula 'group,

R is hydrogen, alkyl having I to l2 carbon atoms, B-methoxyethyl alkenyl having 3 or 4 carbon atoms, propargyl, benzyl, or alkyl substituted benzyl,

R, is straightor branchedchain alkylene having I to 8 carbon atoms, phenylene, phenylene substituted with one or more alkyl groups, or the group '(CH2)mY(CH2),,, wherein Y is oxygen or sulfur and m and n independently of each other are an integer of from 1 to 3.

M is hydrogen or a metal selected from the group consisting of barium, nickel, manganese, calcium. zinc, iron, sodium, cobalt, tin, dialkyl tin, and

2 has a value of from 1 to 4, the value of 1 being the same as the available valence of M.

Examples of R, and R are methyl, ethyl, isopropyl, n-butyl, or n-hexyl. Preferably, R, and R are each a methyl group. Examples of the cycloalkyl groups, as represented by R, and R are cyclohexyl, cyclopentyl, Z-methyl, 3-methyl and 4-methylcyclohexyl, and 2- methyl and 3-methylcyclopentyl. The preferred cycloalkyl groups are cyclohexyl and Z-methylcyclohexyl. Most preferably, R, and R are each a methyl group.

Substituent R, can be hydrogen, alkyl having 1 to l2 carbon atoms, preferably alkyl having 1 to 4 carbon atoms, methyl being particularly preferred, B-methoxyethyl, alkenyl having3 or 4 carbon atoms, preferably alkyl, propargyl, benzyl or alkyl substituted benzyl. Particularly preferred are hydrogen and methyl.

Examples of R are hydrogen. methyl, ethyl. npropyl, isopropyl, n-butyl, isobutyl. n-hexyl, n-octyl, n-dodecyl, allyl, a-methallyl, propargyl, benzyl. a-methylbenzyl, p-methylbenzyl and a-methylbenzyl, p-methylbenzyl and a,p-dimethylbenzyl.

The preferred alkylene residue R is straight-chain alkylene having I to 8 carbon atoms, or the group 2)Hl 2)i| wherein Y is oxygen or sulfur and m and n independently of each other are l or 2, or more preferably 1. Particularly preferred is straight-chain alkylene of l to 8 carbon atoms.

Among the substituents represented by M, hydrogen,

nickel and manganese are preferred. Particularly preferred are hydrogen and nickel.

This invention also related to compositions of matter which are stabilized against ultraviolet light deterioration which comprises a synthetic organic polymer normally subject to ultraviolet deterioration containing from about 0.005% to 5% by weight of the polymer of the compounds of formula I and preferably from 0.01 to 2% by weight.

The compounds as represented by formula I, can be used in combination with other light stabilizers such as 2(Z-hydroxyphenyl)benzotriazoles, 2- hydroxybenzophenones, nickel complexes and benzoates.

The compounds of this invention are stabilizers oforganic material normally subject to thermal, oxidative or actinic light deterioration. Materials which are thus stabilized include synthetic organic polymeric substances including homopolymers, copolymers, and mixtures thereof, such as .vinyl resins formed from the polymerization of vinyl halides or from the copolymerization of vinyl halides with unsaturated polymerizable compounds, e.g., vinyl esters, a,B-unsaturated acids, a,B-unsaturated esters, a,B-unsaturated ketones, a,B-unsaturated aldehydes and unsaturated hydrocarbons such as butadienes and styrene; poly-a-olefins such as high and low density polyethylene, cross-linked polyethylene, polypropylene, poly(4-methylpentene-l and the like, including copolymers of a-olefins; such as ethylene-propylene copolymers, and the like; dienes such as polybutadiene, polyisoprene, and the like, including copolymers with other monomers; polyurethanes such as are prepared from polyols and organic polyisocyanates, and polyamides such as polyhexamethylene adipamide and polycaprolactam; polyesters such as polyethylene terephthalates; polycarbonates such as those prepared from bisphenol-A and phosgene; polyacetals such as polyethylene terephthalate polyacetal; polystyrene, polyethyleneoxide; polyacrylics such as polyacrylonitrile; polyphenyleneoxides such as those prepared from 2,6-dimethylphenol and the like; and copolymers such as those of polystyrene containing copolymers of butadiene and styrene and those formed by the copolymerization of acrylonitrile, butadiene and/or styrene.

Other materials which can be stabilized by the compounds of the present invention include lubricating oil of the aliphatic ester type, i.e., di(l,2-ethylene)- azelate, pentaerythritol tetracaproate, and the like; animal and vegetable derived oils, e.g., linseed oil, fat, tallow, lard, peanut oil, cod liver oil, castor oil, palm oil, corn oil, cottonseed oil, and the like; hydrocarbon materials such as gasoline, mineral oil, fuel oil, drying oil, cutting fluids, waxes, resins, and the like, salts of fatty acids such as soaps and the like; and alkylene glycols, e.g., B-methoxyethyleneglycol, methoxytriethyleneglycol, triethylene glycol, octaethyleneglycol, dibutyleneglycol, dipropyleneglycol and the like.

The compounds of this invention are particularly useful as UV light stabilizers, especially for the protection of polyolefins, for instance, polyethylene, polypropylene, poly(butene-l poly(pentene-l poly(3- methylbutene-l poly(4-methylpentene-l various ethylene-propylene copolymers and the like.

In general, the stabilizers of this invention are employed from about 0.01 to about 5% by weight of the stabilized composition, although this will vary with the particular substrate and application. An advantageous range is from about 0.05 to about 2% and especially 0.] to about 1%.

For addition to polymeric substrates, the stabilizers can be blended before polymerization or after polymerizat/ion, during the usual processing operations, for example, by hot-milling, the composition then being extruded, pre's'se dyblow'inolded or'the' like into films, fibers; filaments; hol'low' spheres' and'thelike". The heat stabilizing properties of these compounds may advantageouslystabilize the polymer against degradation during such processing at the high temperature generally encountered, The stabilizers can alsobe dissolved in suitable solvents and sprayed on the surfaceof films, fabrics, filaments or the like to provide effective stabilization. Where the polymer is prepared from a liquid monomer as in the case of styrene, the stabilizer may. be dispersed or dissolved in the monomer prior to polymerization or curing. These compounds can also be used in combination with other additives such as antioxidants, sulfurcontaining esters such as distearyl-B-thiodipropionate (DSTDP), dilauryl-B-thiodipropionate (DLTDP) in an.

amount of from 0.01 to 2% by weight of the organic material, and the like, pourpoint depressants, corrosion and rust inhibitors, dispersing agents, demulsifiers, antifoaming agents, fillers such as glass or other fibers, carbon black, accelerators and the other chemicals used in rubber compounding, plasticizers, color stabilizers, diand tri-alkyland -alkylphenylphosphites, heat stabilizers, ultraviolet light stabilizers, antiozonants, dyes, pigments, metal chelating agents, dyesites and the like. Often combinations such as these, particularly the sulfur containing esters, the phosphites and/or the ultraviolet light stabilizers will produce superior results in certain applications to those expected bythe properties of the individual components.

The following formula which are in certain instances very useful in combination with the stabilizers of this invention:

ol -11H...

wherein R is an alkyl group having from 6 to 24 carbon atoms; and n is an integer from l to 6. Especially useful compounds of this type are dilauryl-B-thiodipropionate and distearyl-B-thiodipropionate. The above costabilizers are used in the amount of from 0.01 to'2% by weight of the organic material, and preferably from 0.1 to 1%.

Although the compounds of this invention may to some degree also be effective as thermal stabilizers, if the processing of the polymer is carried out at high temperatures it is advantageous to incorporate additional antioxidants.

In most applications, it is desirable to incorporate into the resin composition, sufficient thermal antioxidants to protect the plastic against thermal and oxidative degradation. The amount of antioxidant required will be comparable to that of the actinic stabilizer. Namely, from about 0.005% to 5% and preferably from 0.01% to 2% by weight. Representative of such antioxidants are phosphite esters, such as triphenylphosphite and dibutylphosphite and alkyl arylphosphites such as dibutylphenylphosphite, and the like.

The best results have been obtained withthe preferred class of thermal antioxidants; the hindered phenols. These compounds have been found to provide the represents co-stabilizers best thermal stabilization with the least discoloration in the compositions of the invention. Among these phenolic antioxidants are included the following:

di-n-octadecyl(3-5butyl-4-hydr0xy-5-methylbenzyl )malonate 2,6-di-t-butylphenol 2,2'-methylene-bis(6-t-butyl-4-methylphenol) 2,6-di-t-butylhydroquinone octadecyl-(3,5-di-t-butyl-4-hydroxybenzylthi0)acetate 1,1,3-tris(3-t-butyl-6-methyl-4-hydroxyphenyl)butane l,4-bi's 3,5-di-t-butyl-4-hydroxybenzyl )-2,3-5,6-tetramethylbenzene 2,4-bis-(3,5-di-t-butyl-4-hydroxyphenoxy)'6-(n octylthio)-l,3,5-triazine 2,4-bis-(4hydroxy-3,S-di-t-butylphenoxy)-6-(noctylthioethylthio)-1,3,5-triazine 2,4-bis-(n-octylthio)-6*(3,5-di-t-butyl-4-hydroxyanilino)-l,3,5-triazine 2,4,6-tris-(4-hydroxy-3,5-di-t-butylphenoxy)-1 ,3,5-

triazine n-octadecyl-B-(3,5-di-t-butyl-4-hydroxyphenyl) propionate n-octadecyl-3,5-di-t-butyl-4-hydroxybenzoate 2-(n-octylthio)ethyl-3,5-di-t-butyl-4- hydroxybenzoate stearamido N,N-bisethylene 3-(3,5-di-t-butyl-4- hyd-roxyphenyl)propionate} 1,2-propylene glycol bis- {3(3,5-di-t-butyl-4-hydroxyphenyl)propionate} pentaerythritol tetrakis-{3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate} dioctadecyl-3,5-di-t-butyl-4-hydroxybenzylphosphonate di-n octadecyl-l-(3,5-di-t-butyl-4-hydroxyphenylcthanephosphonate The above phenolic hydrocarbon stabilizers are known and many are commercially available.

The above antioxidants have been listed only for the purpose of illustration and it is important to note that any other antioxidant can beemployed with similar improved results. The above exemplified antioxidants and other related antioxidants which are incorporated herein by reference, are disclosed in greater detail in the following patents: Netherlands Patent Specification No. 67/1119, issued Feb. 19, 1968; Netherlands Patent Specification 68/03498 issued Sept. 18, 1968; US. Pat. Nos. 3,255,191; 3,330,859, 3,644,482, 3,281,505; 3,531,483, 3,285,855; 3,364,250; 3,368,- 997; 3,357,944 and 3,758,549.

The compounds of formula l wherein M is hydrogen 7 may be prepared by reacting a compound of theformula i wherein R,, R and are as defined above. with (a) a cyclic anhydride of the formula wherein p is l 2, or 3, or (b) a cyclic anhydride oftheformula wherein Y is as defined above, or (c) a half methyl ester of a diacid of the following formula wherein R is as defined above or (d) a half methyl ester of a diacid of the following formula wherein m, n, and'Y are as defined above.

Examples of cyclic an hydrides as defined above are succinic, glutanic, and glycolic anhydrides.

Examples of half esters of aliphatic diacids are 0- mono methyl adipate, o-mono methyl malonate. omono methyl sebacate, and o-mono methyl thio dipropionate.

The R substituted compounds of formula ll other than may be prepared by alkylation of the compound of formula 1 III H N -ing metal derivative. 7 I

The metal salts of the present invention can be prepared by treating the acids of formula I with a reactive form of the metal or metal complex, e.g., sodium hydroxide or the like. Alternatively, and preferably in the caseiof metalacomplexes and metals otherzthan the alkali metals, a double decomposition is employed. Thus. for example, a sodium salt of the present invention is treated with nickel chloride. In a similar fashion use of other halides such as manganesechloride, barium chloride and the like results in formation of the correspond- The compounds of formula 'II where R and R are alkyl groups and R is hydrogen are known compounds which may be prepared in accordance with known procedures. The compounds of formula II where R,- and' R;

cform'cycloalkyI-groups and R3 is hydrogen ma be prepared by known procedures, such as those discussed in J. Synthetic Chem. Japan 29 1971 and references contained therein.

The acid anhydrides and half esters of diacids which are reacted with the compounds of formula II may all be prepared by methods well known in the art.

The following examples, presented for illustration and not limitation. will further serve to typify the nature ofthepresentinvention. I I

EXAMPLE I N-(2,2.6,6-Tetramethylpiperidyl-4) Succinamic Acid A. In a l-liter 3-necked flask equipped with a stirrer, thermometer, and condenser equipped with a water separator and nitrogen inlet, were placed 'l'5.95g. (0.] moles-) of 4-.ami'no-2,2,6, tetramethylpiperidine and 500 ml of xylene. The mixture was heated to reflux and a small amountof water was removed-from the reaction with the 'water separator. The reaction mixture was cooled to-40 C and 10.0 g. (0. moles) of suc'cinic anhydride were added. The reaction mixture was heated I to reflux, atwhich point aprecipitate began to-appear.

.The heating u-nder=reflux was continued for 6 hours-and then the reaction mixture was allowed to cool. The 'pr'e glutaramic 8 b. N (2,2.6'.6-tetramethylpiperidyl-4) glycolam'ic c. N-(2.2,6,6 te tramethylpiperidyl-4) tetramethyl succinarnic acid f C. By essentially following procedure '(A) and substituting for the 4-amino-2,2,6.6-tetramethylpiperidine an equivaleht'amour'it of a. 4-amino-l .2,2,ob-pentamethylpiperidine b. t-amino-i -n-dodecyl-2,2,6,6 tetramethylpiperidine l: I

c. 4-amino 1 -b'n zyl-2,2,6.6-tetramethylpiperidine There is respectiyely produced the following'f'compounds i i i a. N-( l,2,2,6,6-pentamethylpiperidyl-4) succinamic acid 4 b. N-( l-n dodecyl-2,2,6,6-tetramethyl 4 succinamic acid i V I c. N-( l-benzyl-2;2,6,6-tetramethyl-4) succin'arnic acid A i EXAMPLE 2 N-(2,2,6, 6;Tetramethylpiperidyl-4) Sebacamic Acid A. In a 250 ml 3-uecked flask equipped wit-h a'stirrer, thermometer andaDeanrStark trap equippedwith a dry-ice condenser, were placed, 15.95 g. (0.] moles) of 4-amino-Z,2,6,6-tetramethylpiperidine, and 21.63 g. (0.1 moleslof O-methyl sebacate. The reactionmixture was heated, with stirring under nitrogen at l.80+2 0.0..C until the methanolwas obtained in the Dean-Stark trap and the dry-ice condenser. The reaction mixture wasthen heatedunder vacuum atthis temperature to remove the last traces of'methanol. The reaction mixture was then cooled and the residue recrystallized from ethanol-water. giving the desired; product ar colorless crystals. v I

B. In the previous experiment A, substituting for the O-methyl sebacate. anequivalent amount of O-methyl adipic acidfzhalf ester, there is produced N-(2,2,6.6'-

tetramethylp'iperidyl4) adipamic acid.

-In-the previous-experiment A. substituting for the 4-amino-2;2,6,'6rtetramethylpiperidine an equivalent amount of- 4-amino-.-l .2,2,6,o-pentamethylpiperidine. there. .is produced N-(==l ,2'.2,6.64pentamethylpiperidyl- '4-)'sebacamic acid.

"Afln a I-lit'i 3-necked flask equipped with a drop -ping funnel, magnetic stirrerand 'nitrogen inlet were mixture was heated slowly to 60 C and stirred for 2 hours. The reactionmixture was then cooled to room temperature and reduced to one-half the original volume under vacuum. To the methanolic solution was I then added 150 mtof isopropanol, and the reaction mixture heated at 60 for 2 hours and allowed to cool to room temperature. The salts deposited on standing were filtered with suction and the filtrate reduced to one-half volume under vacuum. To the reduced filtrate bis [N-(2,2,6,6-Tetramethylpiperidyl-4) was again added l50 ml of isopropanol and the heating and filtration procedure repeated. The filtrate was a. N-(2,2,6,6-tetramethylpiperidyl 4) glutaramici acid b. N-(l,2,2,6,6-pentamethylpiperidyl-4) succinamic acid c. N-(2,2,6,6-tetramethylpiperidyl-4) sebacamic acid There is respectively produced the following Nicompounds 21. Nickel [I bis [N-(2,2,6,6-tetramethylpiperidyl-4) glutaramate] b. Nickel ll bis [N-(l,2,2,6,-pentamethylpiperidyl 4) succinamate] c. Nickel ll bis [N-(2,2,6,o-tetramethylpiperidyl-4) sebacamate] EXAMPLE 4 By essentially following the procedure of Example peratures or in an accelerated artificial light exposure device in order to yield results in a convenient period of time. The tests conducted in polymers using an artificial light exposure deviceis described below:

i a. Sample Preparation 5 mil Film v Unstabilized polypropylene powder (Hercules Profax 6501 is thoroughly blended with the indicated amounts of additives. The blended material is then milled on a two roll mill for 5 minutes at 182C. The milled sheet is then compression molded at 220C into 5 mil thick film under a pressure of 175 psi and water cooled in the press.

b. Testing Method This test is conducted in a FS/BL unit, basically of the American Cyanamid design, which consists of 40 tubes of alternating fluorescent sunlamps and black lights of each). The 5 mil sample film which are mounted on 3 inch X 2 inchlR card holders with A inch X 1 inch windows and are placed on a rotating drum 2 inches from the bulbs in the FS/BL unit. The time in hours is noted for the development of 0.5 carbonyl absorbance units as determined on an lnfrared Spectophotome ter. The development of carbonyl functional groups in the polymer is proportional to the amount of degradation caused by the ultraviolet light exposure.

TABLE I Additive Light Stabilization Data in Polypropylene Time in Hours to 0.5 Carbonyl Absorbance Units N-(2.2,6,6-tetramethylpiperidyl-4) Formulation A" Formulation B succinamic acid 230 795 Nickel Il bis (N-l2,2.6,6-tetramethylpiperidyl-4] succinamate) 2410 1905 Blank 220 640 "Formulation A contains 0.5% additive and 0.2% antioxidant dioctadecyl 3S-di-t-butyl-4-hydrqxybenzylphosphonate "Formulation B contains 0.25% additive. 015% UV absorber 2(2'-hydroxy 3'.5'-di-i-butyl-phenyl)-5-chlorobenzotriazole. and 02% antioxidant dioctadecyl 3.5-di-t-butyl-4-hydroxybenzylphosphonate roportionately good stabilization is obtained when in the compositions of Table l the compounds of this invention are present in the concentrations of 0.1% and 1%.

3(A) and substituting the following metal complexes for nickel chloride:

a. manganese chloride b. zinc chloride c. ferric chloride d. cobalt(ous) chloride there is thus respectively obtained:

example,

1 methylbenzyl )malonate, 2 ,4-bis (n-octylthio )-6-( 3 ,4

Other hindered phenolic antioxidants may be used in place of di-octadecyl(3,5-di-t-butyl-4-hydroxybenzyl)- phosphonate in the above mentioned compositions for di-n-octadecyl a-(3-t-butyl-4-hydroxy %1- di-t-butyl-4-hydroxyaniline) l ,3.5-triazine octadecyl -3-(3,5'-di-t-butyl-4-hydroxyphenyl)propionate, pentmanganese complex of N-[2,2,6,6-tetramethylpiperidyl 4] succinamate b. zinc complex of N-[2,2,6,6-tetramethylpiperidyl- 4] succinamate c. iron complex of N-[2,2,6,6-tetramethylpiperidyl-" 4] succinamate d. cobalt complex of N-[2,2,6,6-tetramethylpiperidyl-4] succinamate EXAMPLE 5 Artificial Light Exposure Test Deterioration of most polymers caused by ultraviolet light is so slow at ambient temperatures, even in the ab sence of stabilizers, that testing of the effects of stabilizers generally must be conducted either at higher teml,3,5-trimethylbenzyl.

The compositions of Table l are also stabilized with chlorobenzotriazole is replaced with the following UV aerythritol-tetrakis {3-( 3,5-di-t-butyl-4-hydroxyphenyl)} propionate, tris-(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 2,6-di-tert-butyl-4 methylphenol, N,- N,N-tris-(3.S-di-tert-butyl-4-hydroxybenzyl)isocyanurate, and 2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)- absorbers:

a. 2-hydroxy-4-me'thoxy-5-sulfobenzophenone trihydrate b. 2-hydroxy-4-n-octoxybenzophenone c. {2,2-thiobis (4-t-octylphenolate)} -n-butylamine nickel II d. p-octylphenyl salicylate' e. 2,2-dihydroxy-4,4"dimethoxybenzophenone f. 2(2'-hydroxy-5'-mcthylphenyl)-benzotriazole.

EXAMPLE 6 cast on a glass plate and the solvent evaporated to yield 1 a uniform film which, upon drying, is removed and cut up, and then pressed for 7 minutes at a temperature of 163C and a pressure of 2,000 pounds per square inch into a sheet of uniform thickness (25 mil). The sheets are then cut into strips approximately 4 X 0.5 inches. A portion of these strips is then measured for percent of elongation in the lnstron Tensile Testing Apparatus (Instrom Engineering Corporation, Quincy, Massachusetts). The remaining portions of the strips are placed in an FS/BL chamber according to Example 7(B) except that the samples are mounted and white cardboard stock and the time to 50% reduction in elongation is" measured. The stabilized polystyrene resin retains its elongation property longer than the unstabilized resin.

EXAMPLE 7 Unstabilized linear polyethylene is solvent blended in methylene chloride with 0.5% by weight of the substrate of nickel bis [N-(2,2,6,6-tetramethylpiperidy1-4) succinamate] and then vacuum dried. The resin is then extrusion compounded on a 1 inch 24/l=L/D extruder, melt temperature 450F (232C) and pressed for 7 minutes at a temperature of 163C and a pressure of 2000 psi into a sheet of uniform thickness of 100 mil. The sheets are then cut into plaques of 2 inch X 2 inch. The plaques are then exposed in a FS/BL exposure device and color measurements made periodically using a Hunter Color Difference Meter Model D25. Polyethylene stabilized with the above compound is found to be much more stable than the unstabilized polyethylene or the polyethylene stabilized only with an antioxi- (121111.

EXAMPLE 8 v A quantity of SBR emulsion containing 100 g of rubber (500 ml of SBR obtained from Texas U.S., Synpol 1500 previously stored under nitrogen, is placed in a beaker and stirred vigorously. The pH of the emulsion is adjusted to 10.5 with a 0.5N NaOH solution.

To the emulsion is added 50 ml of NaCl solution. A 6% NaCl solution adjusted with hydrochloric acid to a pH 1.5 is added in a thin stream with vigorous stirring. When pH 6.5 is reached, the rubber begins to coagulate and the addition is slowed down in order to maintain uniform agitation. The addition of the acidic 6% NaCl solution is terminated when a pH 3.5 is reached. The coagulated crumb-rubber slurry at pH 3.5 is stirred for one-half hour.

The coagulated rubber is isolated by filtration through cheese cloth, and rinsed with distilled water. After three subsequent washings with fresh distilled water, the coagulated rubber is dried, first at 25 mm Hg and finallysto, constant weight under highvacuu mm) at4045C. N g

The driedrubber (25 g is heated under'nitrogen at 125C in a Braben'der mixer and to this isadded with mixing N-(1,2,2,6,6-pentamethylpiperidyl-4) succinamic acid. The composition is mixed for"5 minutes after which it is cooled and compression molded at 125 C into 5 X 0.025 inch plaques.

The plaques are exposed to a xenon arc weathermome'ter and the color measurement (L- b) is made after 45, 125 and 290 hours. The samples stabilized with the above compound are found to be much more light stable than the unstabilized samples. 1

EXAMPLE 9 To 50 g of polyacetal resin containing 0.1% of an; acid scavenger, dicyandiamide, is added 0.2% by weight of nickel 11 bis [N-(2,2,6,6.-tetramethylpiperidyl-4) sebacamate] and milled for 7 minutes at 200C in a Brabender Plasti-recorder. The milled formulation is subsequently pressed into a 40 mil sheet at 215C at 350 psi for seconds then cooled quickly in a cold press at 350 psi. The stabilized sheets are then remolded for 2 minutes at contact pressure and for 3 minutes at 300 psi at 215C to give plaques 1 /2 inch X 2% inch X mil. Thereafter, the testing procedure of Example 9 is followed to determine the light stability of the samples. The stabilized samples are found to be much more stable than the unstabilized samples.

EXAMPLE l0 Unstabilized dried polyethylene terephthalate chips are dry blended with 1.0% of N-(2,2,6,6-tetramethylpiperidyl-4) tetremathyl succinamic acid. 60/10 denier multifilament is melt spun at a melt temperature of 290C. The oriented fiber is wound on white cards and exposed in a Xenon Arc Fadeometer. Color measure- .ments are made periodically with a Hunter Color Difference Meter Model D25. The stabilized samples are found to be much more light stable than the unstabilized samples.

EXAMPLE 1 l a. A composition comprising acrylonitrilebutadienestyrene terpolymer and 1% by weight of N-(l-ndodecyl-2,2,6,6-tetramethyl-4) succinamic acid resists cmbrittlement due to exposure to ultraviolet light longer than one which does not contain the stabilizer.

b. A composition comprising polyurethane prepared from toluene diisocyanate and alkylene polyols and 1.0% by weight of N-(1-benzyl-2,2,6,6-tetramethyl-4) succinamic acid is more stable to sunlight, fluorescent sunlamps, black lights and fluorescent .lights than the unformulated polyurethane.

c. A composition comprising a polycarbonate prepared from bisphenol-A and phosgene and 1% by weight N-(2,2,6,-tetramethylpiperidyl-4) glutaramic acid resists discoloration due to exposure to ultraviolet light longer than one which does not contain the stabilizer.

d. A composition comprising polymethylmethacrylate and 0.25% by weight of N-(2,2,6,6-tetra'methylpiperidyl-4) glycolamic acid resists discoloration due to exposure to ultravioletlight longer than one which does not contain the stabilizer.

EXAMPLE l2 a. A stabilized polyamide (nylon 6,6) is prepared by incorporating therein 0.1% of N-(2,2,6.6-tetramethylpiperidyl-4) succinamic acid. The light stability of the stabilized composition is superior to that of an unstabilized polyamide.

b. A stabilized polyphenylene oxide polymer (prepared by polymerizing 2,6-dimethylphenol is prepared by incorporating therein 0.5% by weight of nickel bis [N'(2,2,6,6-tetramethylpiperidyl-4) succinamate]. The stabilized compositions resist embrittlement due to exposure to ultraviolet light longer than one which does not contain the stabilizerv c. A stabilized crystalline polystyrene is prepared by incorporating therein 0.1% by weight of N-(2,2,6,6- tetramethylpiperidyl-4) tetramethylsuccinamic acid. The stabilized composition resists embrittlement due to exposure to ultraviolet light longer than one which does not contain the stabilizer.

Antioxidants may also be incorporated into each of the above mentioned compositions, for example, di-noctadecyl-a,a-bis(3-butyl-4-hydroxy-5-methylbenzyl) maionate 2,4-bis(4-hydroxy-3,5-di-t-butylphenoxy)-6- (n-octylthioethylthio)-l,3,5-triazine, 2,4-bis(3,5-di-tbutyl-hydroxyphenoxy )-6-(n-octylthio l ,3,5-triazine di-n-octadecyl 3(3,5-di-tbutyl-4-hydroxyphenyl)propionate, respectively.

What is claimed is:

l. A compound of the formula wherein R and R independently of each other are straightor branched-chain lower alkyl having I to 6 carbon atoms, or together with the carbon to which they are bound form a cyclopentyl or cyclohexyl ring,

which is unsubstituted or substituted with a methyl group.

R is hydrogen, alkyl having 1 to l2 carbon atoms, B-methoxyethyl. alkenyl having 3 or 4 carbon atoms, propargyl, benzyl, a-methylbenzyl, pmethylbenzyl, or a,p-dirnethylbenzyl,

R is straightor branched-chain alkylene having 1 to 8 carbon atoms, phenylene, or the group -(-CH ),,,Y(CH wherein Y is oxygen or sulfur and m and n independently of each other are an integer of from l to 3,

M is hydrogen or a metal selected from the group consisting of barium, nickel, manganese. calcium, zinc, iron, sodium, cobalt, tin, dialkyl tin, and

1 has a value of from 1 to 4, the value of z being the same as the available valence of M.

2. A compound according to claim 1, wherein R and R are each methyl,

R is straight-chain alkylene having 1 to 8 carbon atoms or the group -(CH ),,,Y(CH wherein Y is oxygen or sulfur and m and n independently of each other are l or 2.

M is hydrogen, nickel or manganese, and

2 has a value of l or 2. the value of 2 being the same as the available valence of M.

3. A compound according to claim 2, wherein R is straight-chain alkylene having I to 8 carbon atoms and M is hydrogen.

4. A compound according to claim 2, wherein R is the group -(CH- ),,,Y(CH ),,and M is hydrogen.

5. A compound according to claim 2, wherein R is straight-chain alkylene having 1 to 8 carbon atoms and M is nickel or manganese.

6. A compound according to claim 2, wherein R is the group (CH ),,,Y(CH and M is nickel or manganese.

7. A compound according to claim 2, wherein M is hydrogen or nickel.

8. A compound according to claim 3, which is N (2,2,6,6-tetramethylpiperidyl-4-)succinamic acid.

9. A compound according to claim 5, which is nickel bis[N-{2,2,6.6-tetramethylpiperidyl-4-}succinamate]. 

1. A COMPOUND OF THE FORMULA
 2. A compound according to claim 1, wherein R1 and R2 are each methyl, R4 is straight-chain alkylene having 1 to 8 carbon atoms or the group -(CH2)mY(CH2)n-, wherein Y is oxygen or sulfur and m and n independently of each other are 1 or 2, M is hydrogen, nickel or manganese, and z has a value of 1 or 2, the value of z being the same as the available valence of M.
 3. A compound according to claim 2, wherein R4 is straight-chain alkylene having 1 to 8 carbon atoms and M is hydrogen.
 4. A compound according to claim 2, wherein R4 is the group -(CH2)mY(CH2)n-and M is hydrogen.
 5. A compound according to claim 2, wherein R4 is straight-chain alkylene having 1 to 8 carbon atoms and M is nickel or manganese.
 6. A compound according to claim 2, wherein R4 is the group -(CH2)mY(CH2)n- and M is nickel or manganese.
 7. A compound according to claim 2, wherein M is hydrogen or nickel.
 8. A compound according to claim 3, which is N-(2,2,6,6-tetramethylpiperidyl-4-)succinamic acid.
 9. A compound according to claim 5, which is nickel bis(N-(2,2, 6,6-tetramethylpiperidyl-4-)succinamate). 